1. Field of the Invention
The invention is based on an apparatus for metering a reducing agent, in particular a urea or a urea-water solution, in the context of catalytic posttreatment of exhaust gases.
2. Description of the Prior Art
To achieve a reduction in NOx components in exhaust gases, reduction catalytic converters have been developed, especially for Diesel engines, and are typically classified as either so-called SCR catalytic converters (for Selective Catalytic Reduction) or reservoir-type catalytic converters. The so-called SCR catalytic converters are regenerated by delivering a reducing agent comprising urea and/or ammonia, while the so-called reservoir-type catalytic converters are regenerated in so-called rich exhaust gas phases with hydrocarbons from the entrained internal combustion engine fuel.
It is known for the various components of a metering system to be made to communicate via hoses. From German Patent Application 199 46 900.8, an apparatus is known which for removing nitrogen oxides from exhaust gases, for instance from a Diesel engine, meters in urea as a reducing agent. Means intended for this purpose are sometimes secured to a plastic or metal block or integrated with such a block. The metering system described is relatively large and complicated to produce, since it comprises a plurality of components located in line with one another.